Microbial utilisation of natural organic wastes

The waste management strategy for the future should meet the benefits of humanity safety, respect principals of planet ecology, and compatibility with other habitability systems. For these purpose the waste management technologies, relevant to application of the biodegradation properties of bacteria are of great value. The biological treatment method is based upon the biodegradation of organic substances by various microorganisms. The advantage of the biodegradation waste management in general: it allows to diminish the volume of organic wastes, the biological hazard of the wastes is controlled, and this system may be compatible with the other systems. The objectives of our study were: to evaluate effectiveness of microbial biodegradation of non-pretreated substrate, to construct phneumoautomatic digester for organic wastes biodegradation, and to study microbial characteristics of active sludge samples used as inoculi in biodegradation experiment. The technology of vegetable wastes treatment was elaborated in IBMP and BMSTU. For this purpose the special unit was created where the degradation process is activated by enforced reinvention of portions of elaborated biogas into digester. This technology allows to save energy normally used for electromechanical agitation and to create optimal environment for anaerobic bacteria growth. The investigations were performed on waste simulator, which imitates physical and chemical content of food wastes calculated basing on the data on food wastes of moderate Russian city. The volume of created experimental sample of digester is 40 l. The basic system elements of device are digesters, gas receiver, remover of drops and valve monitoring and thermal control system. In our testing we used natural food wastes to measure basic parameters and time of biodegradation process. The diminution rate of organic gained 76% from initial mass taking part within 9 days of fermentation. The biogas production achieved 46 l per 1 kg of substrate. The microbial studies of biodegradation process revealed following peculiarities: (i) gradual quantitative increasing of Lactobacillus sp. (from 10(3) to 10(5) colony forming units (CFU) per ml), (ii) activation of Clostridia sp. (from 10(2) to 10(4)CFU/ml), (iii) elimination of aerobic conventional pathogens (Enterobacteriaceae sp., Protea sp., staphylococci). The obtained results allow to evaluate effectiveness of proposed technology and to determine the leading role of lactobacilli and clostridia in process of natural wastes biodegradation. Our further investigations shall further be concentrated on creation of artificial inoculi for launching of food wastes biodegradation. These inoculi will include active and adapted strains of clostridia and lactobacilli.     

Study of methanogenesis during bioutilization of plant residuals

The waste management strategy for the future should meet the benefits of human safety, respect principles of planet ecology, and compatibility with other habitability systems. For these purposes waste management technologies relevant to application of the biodegradation properties of bacteria are of great value. Biological treatment method is based on the biodegradation of organic substances by various microorganisms.The objectives of our study were: to evaluate the effectiveness of microbial biodegradation of vegetable non-edible residual, using artificial inoculum, and to study the peculiarities of biogas, and possibilities of optimizing or reducing the share of methane. The diminution rate of organic gained 76% from initial mass within 9 days of fermentation. The biogas production achieved 46 l/kg of substrate. The microbial studies of biodegradation process revealed the following peculiarities: (i) gradual quantitative increase of Lactobacillus sp. (from 10(3) to 10(5) colony-forming units (CFU) per ml); (ii) activation of Clostridia sp. (from 10(2) to 10(4) CFU/ml); and (iii) elimination of aerobic conventional pathogens (Enterobacteriaceae, Protea sp., Staphylococci). Chromatography analysis revealed the constant presence of carbon dioxide (up to 90.9%). The methane content measures revealed traces 0.1-0.4%. However, when we optimized the methane production in "boiling layer" using methanogenic granules, the amount of methane in biogas reached 80-90%. Based on the results obtained the artificial inoculum was created which was capable of initiating biodegradation of vegetable wastes. This inoculum consisted of active sludge adapted to wastes mixed with excretea of insects which consume plant wastes. Using this inoculum the biodegradation process takes less time than that using active sludge. Regulation of methane concentration from traces to 90% may be achieved by adding methane reactor to the plant digester.     

离心喷嘴偏心和凸凹对双旋流器空气雾化特性的影响

为深入了解离心喷嘴偏心和凸凹2种错位形式对反向双旋流空气雾化喷嘴雾化特性的影响,采用高清照相机和相位多普勒粒子分析仪(PDPA),对不同错位程度的双旋流空气雾化喷嘴的雾场形态、索太尔平均直径、罗辛-拉姆勒(Rosin-Ramumber)分布进行试验研究。试验结果表明,喷嘴偏心将导致雾场偏移并且不对称,破坏回流区,同时液雾索太尔平均直径变大,分布指数变小,喷嘴内凹对雾场形态和液雾索太尔平均直径影响很小,但使分布指数减小;喷嘴外凸对雾场形态影响很小,但使液雾索太尔平均直径和分布指数显著增大。